Radon levels high in Portland

PORTLAND — The percentage of Portland-area homes with elevated levels of the cancer-causing gas radon is double the national average, according to new estimates.

The figures show that about 25 percent of homes in the Portland area have a radon level above what the U.S. Environmental Protection Agency says should prompt fixes to keep the radioactive gas outdoors, said Scott Burns, a Portland State University professor who worked with students to compile radon tests statewide.

The new results, the first update since 2003, drew on testing in 33,000 homes in the Portland area — 10 times more than last time. The expanded data also showed high levels in metro areas previously unreported, such as Clackamas, Gladstone, Lake Oswego, Sherwood and Wilsonville.

Radon is the second-leading cause of lung cancer in the United States after smoking, killing about 21,000 people each year, according to the EPA.

The odorless, invisible gas seeps in from the ground through construction joints and gaps in foundations. The risk is higher in Portland because granite-infused sediment, relatively high in uranium, washed into the region from the torrential Missoula Floods during the last ice age. Radon is a byproduct of uranium's breakdown.

“It's a geological hazard that can be dealt with cheaply,” Burns told the newspaper. “We need to reduce the amount of radiation in our lives, and this is one way of doing that.”

The best time to test for radon is winter, when levels tend to be highest. Exposure is typically greatest in basements.

Health officials recommend radon tests for all homes because two places right next to each other can have wildly different results, even those in ZIP codes considered low risk.

“The tests are not difficult, and if you find out you don't have a problem, you've bought some very reasonably priced peace of mind,” said Mike Brennan, a radiation health physicist with the Washington State Department of Health.